In the use of a refrigerator-freezer, particularly during periods of high ambient temperature, the fresh food compartment door is often opened to recover cold beverages and other items. Each time the door is opened, chilled air within the fresh food compartment passes through the door and warm air passes into the fresh food compartment. Under some warm weather conditions where the door is repeatedly opened, the refrigerating capacities during continuous operation are not sufficient to maintain the temperature of the fresh food compartment with a preselected temperature range of about 1.degree. to about 9.degree.C. However, since the door of the freezer compartment is less frequently opened, it has been discovered that additional cooling capacities reside in the freezing compartment of the refrigerator-freezer. The problem therefore resides in developing an apparatus which provides for controlled passage of chilled air by convection from the freezer compartment into the fresh food compartment, is responsive to the temperature of the fresh food compartment, and is responsive to opening and closing the refrigerator door.
Attempts have heretofore been made to provide additional chilled air to the fresh food compartment by providing a temperature responsive air control means in the air discharge conduit serving the fresh food compartment. An example apparatus is shown in U.S. Pat. No. 3,375,679-Helsel. However, this device is effective only during the operation of the refrigeration cooling system, does not provide for the passage of air by convection from the freezer compartment into the fresh food compartment, and does not function in response to opening and closing the fresh food compartment door.
The apparatus of this invention provides for chilled air to pass by convection from the freezer compartment into the fresh food compartment in response to opening the refrigerator door and additional chilled air to pass by convection into the fresh food compartment in response to the temperature of the fresh food compartment being at a temperature greater than a preselected value. By utilizing the apparatus of this invention, the temperature within the fresh food compartment is maintained at a desirable value for preserving food during hot weather conditions and repeated openings of the refrigerator door.